Here at Mystic Aquarium, one of our beloved northern fur seals suffers the lasting consequences of domoic acid poisoning, a potentially deadly neurotoxin. Yura came to the Aquarium in 2019; however, Yura’s story starts in July 2018 when she was stranded on a California beach and rescued by The Marine Mammal Center. At the time, she was pregnant with a male pup, Tuk, who was born the night she was rescued. The animal rescue team immediately noticed signs of domoic acid poisoning in Yura and began treatment to save her life. An MRI was performed that showed non-reversible neurological lesions and she was deemed non-releasable due to her seizure activity and need for lifelong seizure medication. Tuk, her young pup, was also deemed non-releasable as domoic acid can be transferred to unborn pups and through nursing after birth. Tuk found his forever home alongside Yura at Mystic Aquarium, which is uniquely qualified to care for animals with neurological disorders.
First discovered in marine mammals in 1998, domoic acid is a naturally occurring toxin found in harmful algae blooms. The biotoxin is produced by specific types of algae and is commonly associated with “Red Tide”, an algae bloom that creates a reddish color on the water’s surface and contains Pseudo-nitzschia australis. Domoic acid is not harmful in small quantities and does not affect its primary consumers, which consist mostly of small fish and shellfish on the seafloor. However, the toxin is harmful to larger predators due to biomagnification, the increase in concentration of a pollutant from one link in a food chain to another and can cause permanent neurological damage.
Domoic acid can affect many different species of animals, including northern fur seals, otters, seabirds, sea lions, and even humans. The biotoxin attacks the brain and heart, causing seizures, physical disabilities and even heart failure. Over time, the toxin will leave the animal’s system, but repeat exposure can lead to permanent damage. Veterinarians can combat domoic acid by flushing an animal’s system with fluid, providing a toxin-free food source and administering anti-seizure medication. In many cases, animals rescued from domoic acid poisoning can be released back into the wild if physical abilities return, bloodwork is normal, and there are no signs of seizures.
Today, you can visit Yura and Tuk at the Pacific Northwest habitat as they continue their important work as animal ambassadors to inspire people to leave Mystic Aquarium as stewards of their ocean environment. While scientists don’t know precisely what is causing the influx of domoic acid in the ocean, many contributing factors include climate change, agricultural and urban runoff, coastal development, and eutrophication from fertilizers. Through important research, scientists can better understand domoic acid causes and apply those findings to the interconnections of our ecosystems.